1. Field of the Invention
The present invention relates to a field of electric connection, and in particular, to an electrical receptacle terminal.
2. Description of the Related Art
It has been known that the existing electrical receptacle terminal generally comprises a contact portion and a connecting portion. The connecting portion 200 is in electrical connection with an electrical cable by splicing, and the contact portion is in electrical connection with an inserted male terminal through an elastic contact piece. Usually, the existing electrical receptacle terminal adopts an integrated design. The electrical receptacle terminal is generally rigidly connected to the elastic contact piece. Once an electrical cable is inserted into the electrical receptacle terminal, the latter has an increased mass and is restrained by the electrical cable. As a result the electrical receptacle terminal can not do a forward and backward movement easily. Thus, once the electrical receptacle terminal is used in a strong jolting environment (for example, in a vehicle), there is high likelihood that a slightly motion for the male terminal inserted into the elastic contact piece relative to the electrical receptacle terminal may occur. After a long period in which the motion occurs has lapsed, the surface (usually coated with tin thereon) of the electrical receptacle terminal will be scrapped to form a non-conductive oxide layer so as to disable the electric connection of the electrical receptacle terminal. This phenomenon is called as fretting corrosion.
As shown in FIGS. 1 and 2, aiming to effectively overcome fretting corrosion, U.S. Pat. No. 5,611,717 discloses a miniature anti-fretting receptacle terminal. The receptacle terminal comprises a connecting portion 8, a contact portion 14, and a spring portion 12 located between the connecting portion 8 and the contact portion 14. The spring portion 12 comprises two pairs of U-shaped elastic portions 22, 24 located on the side walls, respectively. Each of the elastic portions 22, 24 respectively comprises a pair of elastic beams 26, 27 and 28, 29, and, the upper portions of each pair of the elastic beams 26, 27 and 28, 29 are connected by U-shaped bridge portions 30, 32, respectively.
As shown in FIGS. 1 and 2, in the miniature anti-fretting receptacle terminal disclosed by U.S. Pat. No. 5,611,717, a spring portion 12 is provided between the connecting portion 8 and the contact portion 14 of the receptacle terminal, as such, the whole receptacle terminal is much more flexible. Therefore, this receptacle terminal itself can move in a forward and backward manner without the restriction from the inserted electrical cable. Thus, when the receptacle terminal is used in a strong jolting environment (for example, in a vehicle), there is no slightly motion for the male terminal inserted into the elastic contact piece 50 relative to the electrical receptacle terminal, instead, it moves together with the spring portion 12 of the electrical receptacle terminal, so as to effectively eliminate fretting corrosion problem.
However, according to the disclosure of U.S. Pat. No. 5,611,717, a spring portion is provided between the connecting portion and the contact portion of the receptacle terminal. The receptacle terminal requires more materials and has a more complicated structure. Hence, the cost is relatively high. Furthermore, the connecting terminal and the spring portion of this receptacle terminal are exposed to the environment, and may be easily damaged or even broken off.
In order to overcome or alleviate at least one aspect of the above mentioned technical problems, it is necessary in the art to provide a novel electrical receptacle terminal with simple structure and low cost which has the advantages of eliminating fretting corrosion problem and diminishing the impact from external force.